... a 275% crop of the original image which was 60mp, I believe I am allowed to do this math but a 300mm*2.75 = 825mm lens .... so bam, medium format 825mm lens which is a stop or so faster then this 17k monster!

So you are cropping from a 300mm, f/4.5 lens to a portion of the image smaller than 36x24mm? Then you might as well use a 300mm lens on a 36x24mm format camera, still allowing a crop to the same FOV. And with more pixels on the same subject matter if the camera is a D800(E), for which there are 300mm lenses far less expensive than the Hasslebald one (and faster).

You will need the smallest crop, for any lens FL, on the Sony A77 or NEX 7, 24MP on APS-C.

Yes, I thought of that after I posted: the cheapest and highest resolution alternative to that massive 2.75x crop from a 300mm lens on a DMF body is using a 300mm lens on a sub-35mm format body like the Nikon D5200.

By the way, as an alternative to my previous idea of replacing the 800/5.6 with a 600/4 lens and 1.4x on an FX body, one could replace the TC by a DX format body, and so use half the ISO speed.

I was being somewhat light hearted....since it decidedly was not the right tool for that job, but it was what I happened to have with me when I was in this situation, D3s was back at the hotel....but fact remains that sometimes medium format cropping helps and can still give you something great.

My numbers were based off how I cropped the original P65+ image to get to the final result.